1. Field of the Invention
This invention is related to the field generally of biologically based herbicides, including the use of dried distiller's grain as an aid to plant production, and to such plant production as part of a fuel producing regime.
2. Description of Related Art
A large part of the production cost of grain has been in the control of weeds with herbicides. Weed control is implemented for a number of reasons. Greater yields of grain may occur when certain weed populations are kept low. Automated harvesting of grain is facilitated with lower interference from weeds and less debris is captured during the automatic harvesting process.
The cost of weed control may rival the net profit of the final product. The cost of herbicide application and use is a combination of bulk cost of the herbicide, labor, fuel, equipment, and other factors. Recently, genetically modified varieties of crops have been put into production which are able to tolerate direct aerial or ground application of certain herbicides. With such genetically modified varieties, the cost of weed suppression shifts from labor and fuel and instead is weighted by the costs for special seeds and seed specific chemicals. Genetically modified varieties have certain distinct drawbacks. One drawback is that often the growers cannot save their own seed without violating patent rights. Further, growers are concerned that the use of seed from a monopolized source may subject them in the future to higher costs unregulated by normal market forces. Also, genetically modified crops face significant export restrictions, and cannot be sold in high premium organic markets.
Chemically active herbicides represent a potential weed control technique. These chemical herbicides may be broken down into pre-emergent and post-emergent herbicides. Pre-emergent herbicides typically interfere with germination of weed seeds, whereas post-emergent herbicides kill the weeds after the weed seeds have germinated and weed growth has begun.
Pre-emergent herbicides may be effective when present at the required dosage at the time weed seed germination is ready to occur. However, this timing issue points out a major problem with respect to pre-emergent herbicides. Specifically, if the pre-emergent herbicide is not applied, or degrades, prior to weed seed germination, the weed seeds are free to germinate and begin growing to mature weeds. Additionally, pre-emergent herbicides are typically weed type specific and are not equally effective against all types of weeds. The timing problem present with pre-emergent herbicides may be avoided by employing post-emergent herbicides and by employing post-emergent herbicides only after the weed seeds have germinated and the weeds are actively growing. However, most available post-emergent herbicides are non-selective herbicides and will therefore kill desirable plants in addition to weeds. Except in the case of genetically modified crops, post-emergent herbicides cannot be used in proximity to crops.
Many pre- and post-emergent herbicides also suffer from another problem. Specifically, many pre-emergent and post-emergent herbicides are either moderately or highly toxic to humans and animals, and may thereby have damaging effects far beyond the intended weed control effect. Toxic herbicides may cause injury either immediately or over the long term to persons applying the herbicides and to persons present when the herbicides are applied. Also, residual concentrations of toxic herbicides that remain in the soil or water after application of the herbicide may pose a significant threat to human beings and to animals, including land-based animals and amphibians and fish, upon contact with the treated area or runoff from the treated area. Furthermore, public alarm about the use of toxic chemicals as herbicides and their potential widespread and long-term effects on environmental quality dictate against the continued use of these toxic herbicides. Use of chemical herbicides are not permitted in high value organic agriculture.
A drawback of chemically active herbicides coupled with chemical fertilizer, known as weed and feed mixtures, is that they require multiple components. In addition to the serious and harmful side effects of these chemicals, they often require separate applications, have shorter periods of action, and require specially trained personnel to apply, handle, and clean up the material. Another drawback of chemically active herbicides is that they may damage mycorhyzzal symbiotic fungi and other beneficial soil life. Chemical fertilizer may be toxic to beneficial soil organisms, for example earthworms, humus, and related organic matter. Destruction of these compounds reduces the ability of the soil to retain nutrients.
Organic vegetable growers do not use chemical herbicides or genetically modified crop varieties in their production. One of the weed control strategies used in the production of high value organic vegetables is the use of corn gluten meal. Testing by organic farmers has shown that corn gluten meal works as a pre-emergent herbicide on a wide variety of broadleaved weeds and some grasses. A pre-emergent herbicide works well for certain types of vegetable production where transplanting is the norm. The herbicidal effects of corn gluten meal seem limited to germinating seed and does not affect most transplanted crops.
The wet milling of corn produces corn gluten meal as one of its primary products. Corn gluten meal is one of many products extracted from corn during the wet milling process. A description of processes that produce corn meal is seen in U.S. Pat. No. 6,610,867 to Jakel et al. which is hereby incorporated by reference in its entirety. Other descriptions are seen in U.S. Pat. No. 6,703,227 to Jakel et al, U.S. Pat. No. 6,545,191 to Stauffer, and U.S. Pat. No. 6,509,180 to Verser which are hereby incorporated in their entireties by reference. Corn gluten meal is extracted from corn following an acid bath soaking period. Corn gluten meal may be spread on the surface of the soil after seeding or tilled in shallowly prior to seeding. The weed suppression effect of corn gluten meal continues for weeks after application. The use of corn gluten meal in this fashion is permitted for use in organic agriculture. The National Organic Standards Board (NOSB) lists corn gluten meal as a organic approved herbicide in the restricted class. However, the corn from which the corn gluten meal is derived cannot be a genetically engineered variety.
A drawback of the use of corn gluten meal as an herbicide has been its relatively high cost. Corn gluten meal has been in high demand, especially in Europe, as both chicken and cattle feed. Corn gluten meal may produce brightly colored yokes when fed to laying hens and this is a consumer preference.